1. Field of the Invention
The present invention relates to a disk drive and more particularly to a magnetic disk drive having a flex clamp with an integrated VCM plate connection, a single-sided flex circuit cable having a Z-shaped grounding portion, or both.
2. Description of the Prior Art and Related Information
A typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA). The HDA includes an enclosure having a base and cover, at least one magnetic disk (disk), a spindle motor for rotating the disk, and a head stack assembly (HSA) that includes a transducer head (head) for reading and writing data.
The HSA is controllably positioned by a servo system in order to read or write information from or to particular tracks on the disk. The typical HSA includes:(1) an actuator assembly that moves in response to the servo control system; (2) a head gimbal assembly (HGA) that extends from the actuator assembly and biases the head towards the disk; (3) a flex circuit cable for carrying read/write signals and a ground line to and from the head; (4) a "flex clamp" for clamping a connector end of the flex circuit cable to a connector port on the base; and (5) a ground connection to the base at the connector end of the flex circuit cable.
As to the actuator assembly, the industry presently prefers a "rotary" or "swing-type" actuator assembly which conventionally comprises an actuator body that rotates on a pivot assembly between limited positions, a coil portion that extends from one side of the actuator body and interacts with one or more permanent magnets held by "VCM plates" to form a voice coil motor, and an actuator arm that extends from an opposite side of the actuator body to support the HGA.
As to the HGA, a typical HGA includes a load beam, a gimbal, and a head or slider. The load beam has a spring function which provides a "gram load" biasing force and a hinge function which permits the head to follow the surface contour of the spinning disk. The load beam has an actuator end that connects to the actuator arm and a gimbal end that connects to the gimbal which carries the head and transmits the gram load biasing force to the head to "load" the head against the disk. A rapidly spinning disk develops a laminar air flow above its surface that lifts the head away from the disk in opposition to the gram load biasing force. The head is said to be "flying" over the disk when in this state.
With reference to FIG. 1, a prior art magnetic hard disk drive, a portion of which is shown, requires five screws 801-805 and five corresponding threaded holes 841-845 in the base 840 to attach voice coil motor (VCM) plates 850 and 860, a flex circuit cable 830, and a flex clamp 820 to the base. Two screws 802, 803 secure the VCM plates 850, 860 to the base 840 via corresponding aperture pairs (852;862), (853;863), and threaded holes 842, 843. The lower VCM plate 860 includes a permanent magnet 864. Two screws 801, 804 secure the flex clamp 820 and flex circuit cable 830 to the base 840 via corresponding aperture pairs (821;831), (824;834) and threaded holes 841, 844. One individual screw 805 connects a metal grounding contact 837 of the flex circuit cable 830 to the base 840 via an aperture 835 and threaded hole 845.
However, using screws presents some potential drawbacks such as:
the cost of the screws; PA1 the time and cost required for positioning and driving the screws; PA1 the time and cost of forming threaded screw holes in the base to receive the screws; PA1 the environmental leak paths that may be caused by the screw holes in the base; and PA1 the particulate contamination that may be generated by fastening each screw to a corresponding screw hole.
Accordingly, there is a need for a magnetic disk drive that reduces the number of screws needed to secure the VCM plates, flex clamp, and flex circuit cable including the ground connection to the base.